This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | -1 |
| 3 | 0 |
| 4 | 2 |
| 5 | -4 |
| 6 | 6 |
| 7 | -8 |
| 8 | 7 |
| 9 | 0 |
| 10 | -14 |
| 11 | 40 |
| 12 | -73 |
| 13 | 88 |
| 14 | -70 |
| 15 | -4 |
| 16 | 194 |
| 17 | -524 |
| 18 | 926 |
| 19 | -1234 |
| 20 | 1078 |
| 21 | 140 |
| 22 | -3038 |
| 23 | 7900 |
| 24 | -14065 |
| 25 | 18858 |
| 26 | -16368 |
| 27 | -2710 |
| 28 | 48861 |
| 29 | -127826 |
| 30 | 228788 |
| 31 | -306494 |
| 32 | 263377 |
| 33 | 55144 |
| 34 | -829014 |
| 35 | 2160120 |
| 36 | -3865459 |
| 37 | 5172792 |
| 38 | -4405043 |
| 39 | -1118324 |
| 40 | 14530041 |
| 41 | -37606792 |
| 42 | 67159094 |